Spinneret for the manufacture of staple fiber filaments



March 8, 1955 HQLZMANN 2,703,433

. SPINNEREET FOR THE MANUFACTURE OF STAPLEFIBER FILAMENTS 2 Sheets-Sheet1 Filed Dec. 6. 1949 March 8, 1955 H. HOLZMANN 2,703,433

SPINNERET FOR THE MANUFACTURE OF STAPLE FIBER FILAMENTS Filed Dec. 6,1949 2. Sheets-Sheet 2 -oooooo OOO QOOOO OOO //YVEA' rag 41- TOPIYEYSUnited States Patent SPINNERET FOR THE MANUFACTURE OF STAPLE FIBERFILAMENTS t Hermann Holzmann, Hanan on the Main, Germany, as-

lignor to Deutsche Goldund Silber-Scheideanstalt vormals Roessler,Frankfurt am Main, Germany, a cor poratlon of Germany ApplicationDecember 6, 1949, Serial No. 131,331 In Germany December 3, 1948,

Public Law 619, August 23, 1954 Patent expires December 3, 1968 Claims.(c1. 18-8) This invention relates to spinnerets for the manufacture ofstaple fibre filaments, especially in the viscose process and pertainsmore particularly to an improvedspinneret bottom with annular channelswithout spinning openings. The object of this invention is to provide aspinneret whereby at least one annular channel without spinning holes isarranged in addition to the radial hole-tree channels.

A further ob ect is to provide a spinneret with concentric annularchannels whereby the intervals between the annular'channels increasetowards the center of the spinneret bottom. Other objects of myinvention will be apparent as the detailed description of my inventionproceeds.

The main disadvantage attendant upon the use of multi-perforatedspinnerets for the manufacture of staple fibre filaments, especiallyaccording to the viscose process, was the ditficulty in directing theprecipitant bath fluid through the thick bundle of filaments to theholes at the center of the spinneret bottom. Furthermore, theprecipitant bath becomes already partly neutralized or diluted insidethe bundle of filaments and is therefore devoid of the same coagulatingefiect in the surrounding of the spinneret axis.

As it is known, this difliculty was soon overcome by arranging theopenings in the spinneret bottom with interspaced channels for an easierinflow of the precipitant bath fluid towards the center of the spinneretinstead of squally distributing the spinning holes over the wholespinneret bottom. Even in varying the shape and size of the channels,the latter are always arranged in radial direction.

I have discovered that the spinning capacity of multiperforatedspinnerets may be most favorably influenced, if, for instance,concentrically arranged annular channels are provided in addition to theradial channels. My invention relates therefore to a spinneret for theproduction of staple fibre filaments according to the viscose process,with radial hole recesses at the spinneret bottom whereby at least oneannular channel exempt from openings is arranged in addition to theradial channels without spinning holes. These concentric annularchannels connect the radial channels with each other, thereby causing afurther guiding of the precipitant bath inflow which intensifies thedistribution of the filament bundle.

Furthermore, this device also counteracts a too extensive deviation ofthe precipitant bath fluid in the direction of the filament bundlecenter. According to my invention the division of the spinneret bottominto radial and concentric recesses makes possible narrowing theintervals between the spinning holes in their respective bottompartitions to a higher degree than it was hitherto known. In my newspinneret the effect which is exerted by the particular subdivision ofthe spinneret bottom may be still further enhanced by arranging theconcentric annular channel recesses containing the spinning openings ingrowing intervals, beginning at the periphery and i. e. the two outerannular channels have the same width, whilst the centripetally ad ustedthird and fourth channels are narrower and so fort l have turther roundtrom experiments that spinnerets containing the new annular cnannels inaddition to radial channels yield an excellent unnorm quanty ot'filament. 'lhese spinnerets are alSO more IeSlSKaDC against wearing awayone to continued usage and superior to spinnerets with radial channelsonly. Moreover, the spinnerets according to my nvention may contain asuprismgly large number of spinning holes in spite of recesses, due tothe diminished intervals between the spinning holes withoutdeteriorating the quality of the tnamenr. 'lhus it is possible to obtainespecially ravorable conditions for the manufacture or staple norewhilst observing the most economical use of the precious spinneretmaterial. The new spinneret is thererore a distinct improvement in theproduction of rayon, especially staple hbre filaments.

l have illustrated a preferred form of my device in the accompanyingdrawings. Fig. l discloses the spinneret bottom in a plan view of thedevice. Fig. 2 discloses a segment of rig. 1 in a larger scale.

in Fig. 1 l have shown tour concentrically arranged annular channelsexempt from holes (bi, b2, bz, hr) in addition to the usual radialchannels without spinning holes, as indicated in Fig. 2, the intervalsbetween the annular channels b1, b2, b3 and b4 (namely, the width of 02,0a and 04) increase from the periphery to the center of the spinneretplate bottom. Each pair of the annular channels has the same width.Thus, the width of the annular channels b1 and 11: corresponds to spaced, whilst the width of the annular channels ha and b4. is in accordancewith the narrower space e. The series of the spinning holes are broaderat the center of the spinneret bottom. Therefore the outermost row ofholes shows the smallest width (or), the innermost row of holes thegreatest width (03).

The channels may be carried out either in the form of planes withoutopenings or in the form of grooves or notchings.. It is even possible tonotch only one kind of the channels, i. e. either the radial or theannular channel whereby the grooved channels may die out into the planeones.

What I claim is:

l. A spinneret for the production of staple fibre filaments having aplate provided with a plurality of spinning openings arranged about acenter in groups spaced from each other to provide concentric annularopening free channels in said plate and to provide radial opening freechannels in said plate extending towards said center between said groupsof openings, said radial channels communicating with said concentricannular channels, the spacing between the groups of spinning openleadingto the center of the plate. A further advantage ings providing theradial and annular opening-free channels being substantially greaterthan the spacing between the individual spinning openings in each group,and the openings in eachgroup being arranged in a plurality of rowsdisposed at different distances from said center.

2. A spinneret for the production of staple fibre filaments having aplate provided with a plurality of spinning openings arranged about acenter in arcuate groups spaced from each other to provide concentricannular opening free channels in said plate and to provide radialopening free channels in said plate extending toward said center betweensaid arcuate groups of openings, said radial channels communicating withsaid concentric annular channels, the spacing between the groups ofspinning openings providing the radial and annular opening-free channelsbeing substantially greater than the spacing between the individualspinning openings in each group, and the openings in each group beingarranged in a plurality of rows disposed at difierent distances fromsaid center.

3. A spinneret for the production of staple fibre filaments having aplate provided with a plurality of spinning openings arranged about acenter in arcuate groups spaced from each other to provide concentricannular opening free channels in said plate and to provide radialopening free channels in said plate extending toward said center betweensaid arcuate groups of openings, said radial channels communicating withsaid concentric annular channels, the spacing between the groups ofspinning openings providing the radial and annular openingfree channelsbeing substantially greater than the spacing between the individualspinning openings in each group, the openings in such groups beingarranged in a plurality of rows disposed at different distances fromsaid center have a greater width in the radial direction than arcuategroups further out from the center.

4. A spinneret in accordance with claim 3, in which the width of theannular opening free channels near the center is less than the width ofthe annular channels further out from said center.

5. A spinneret for the production of staple fibre filaments having aplate provided with a plurality of spinning openings arranged about acenter in arcuate groups spaced from each other to provide concentricannular openingfi'ee channels in said plate and to provide radialopening free channels in said plate extending toward said center betweensaid arcuate groups of openings, said radial channels communicating withsaid concentric annular channels, the spacing between the groups ofapinning openings providing the radial and annular opentug-free channelsbeing substantially greater than the spacing between the individualspinning openings in each group, the openings in such groups beingarranged in a plurality of rows'disposed at itferent distances from saidcenter and in which the width of the annular opening free channels nearthe center is less than the width of the annular channels further outfrom the center.

' References Cited in the tile of this patent FOREIGN PATENTS 321,344Germany May 3t, 1920 395,524 Germany May 22, 1924 286,342 Great BritainFeb. 20, 1928 647,913 France Aug. 6, 1928 809,230 Germany July 26, 1951

